The present invention is concerned with a process for the production of ethylene co-polymers under elevated pressure with the use of a peroxide catalyst, as well as with a catalyst for carrying out this process.
Processes for the polymerisation of ethylenically-unsaturated monomers under elevated pressure and elevated temperature in the presence of a peroxide catalyst are known.
DE-A-3322329 describes a process for the production of polyethylene by the polymerisation of ethylene and a co-polymerisable monomer in the presence of a catalyst of a transition metal derivative and an organo-aluminium derivative in which an organic peroxide is added to the polymerisation product at the outlet from the reaction zone in order thereby to deactivate the residual catalyst.
JP-B-79031039 describes the (co)polymerisation of aliphatic .alpha.-olefins with the use of a catalyst system which consists of a trialkylaluminium, an electron donor and a peroxide.
D. Yatsu et al., American Chemical Society, Division of Polymer Chemistry, Polymer Reprints, Vol. 16, No. 1, April 1975, pages 373 to 378 described the co-polymerisation of ethylene and vinyl acetate in the presence of a three-component catalyst system of triethyl aluminium, a Lewis base and a peroxide.
NL-A-268 250 describes a low pressure co-polymerisation of olefins containing 2 to 4 carbon atoms with a vinyl ester. The process is carried out at a pressure of &lt;70 ats and at a temperature of -80 to +60.degree. C. As catalyst, there is used a mixture of peroxide and an organo-aluminium compound.
It is an object of the present invention to provide an economic process for the co-polymerisation of ethylene with further polymerisable monomers in the presence of a peroxide catalyst at high pressures and a high temperature with which an improvement of the polymer yield per unit weight of peroxide used can be achieved.